| 摘要 |
PURPOSE:To decrease input impedance and to decrease noises, by providing a Schottky barrier diode structure for a diode for the gate of a junction type field-effect transistor used for an electret capacitor microphone. CONSTITUTION:A Schottky barrier diode SBD and a P-N junction diode Di2 are connected between the G and the S of a junction type field-effect transistor (J-FET) in parallel in the reverse directions. In an N-type semiconductor region 2 surrounded by a P-type semiconductor region l, a P-type region is formed. A gate region 3 of the J-FET or the diode region of Di2 is formed. In the N-type region 2, an N<+> type region 6 is formed. Concentration is made high so that ohmic contact of the diode, a source S and a drain D can be obtained. An SBD part 7 is formed between a metal wiring 9 and the u-type semiconductor region 2. A P-N junction part 4 is provided, aud an insulating film 8 is provided. |
